On Saturday 10 March 2018 07:50:39 Lukas Wunner wrote:
Pretty much all modern Nvidia GPUs do have an integrated HDA controller, however it's possible to hide it by clearing a bit at offset 0x488 in the GPU's config space. Some BIOSes hide the HDA if no external display is attached.
I could imagine that the BIOS of the Dell machines in question hides the HDA if Switchable Graphics is enabled. If that is the case, be aware that there's an ongoing discussion to always expose the HDA controller because the behavior of some BIOSes to only expose the HDA when a display is attached causes massive problems with Linux' HDA driver: https://bugs.freedesktop.org/show_bug.cgi?id=75985
If we decide to always expose the HDA controller on Nvidia cards, you may need to also match for the Nvidia vendor ID here.
This is probably the example of reason why current solution based on vendor id is fragile and could be broken in future... if such changes to unhide devices are going to be implemented.